RITA MAE BROWN loves Mark Twain. She says he was American to the marrow, like herself. Somehow Mark Twain's Americanness is more comfortable than Rita Mae Brown's. Back in the 19th century, there was still room for innocence. Now it's a little harder to come by, and most of our attempts take the form of "The Waltons"--self-congratulatory and insipid. Molly Bolt of Rubyfruit Jungle, Brown's previous book, came close. But in Six of One, Brown tackles a much more serious task. Rubyfruit Jungle was a sad-funny autobiographical sketch of a young lesbian growing up. Six of One is an attempt to construct a fictional feminist history of the 20th century in America, through the lives of women living in a small town in Maryland.

Celeste Chalfonte is the witty intellectual lesbian heiress, living with her beautiful young lover Ramelle in her mansion on the hill. Cora is her lifetime friend and servant. Julia and Louise are Cora's daughters, eternally at each other's throats and occasionally remembering they love each other. Julia, we eventually learn, is the mother of the narrator, a young bisexual writer. Evidently Rita Mae has now decided men are all right.

It's a fun book. The dialogue is rich and raunchy, often delightful. And the reader wants so much to believe that Brown's right: that women knew how to love each other before 1968, that female solidarity is not an invention of the Millets and Morgans. The problem is with the writing itself.

In the first place, Brown has a lousy editor. I am always annoyed by authors who write long passages of dialogue without identifying who is speaking, so one must count back the lines to find out who said what. In a couple of places in Six of One, Brown loses track herself, and has people talking to themselves in a most unlikely manner. This should have been caught before the book went to press.

The style is uneven. When the dialogue is explained, it is sometimes done well and unobtrusively, but at other times the language sounds like a G.E. instruction manual ("Cora placed the items on the table.").

Brown uses painfully obvious devices to fill the reader in on past events. Out of nowhere, a character remarks: "Did they ever prove that Cassius Rife killed Cora's father?" One of the cast marries a Japanese man. He is apparently the only Japanese in town. No explanation is given of how he got there. When World War II breaks out, we hear that his wife bashes a Fed over the head with an umbrella when they come to take him away to an internment camp. He reappears later in the book, casually, and again no explanation is given.

And it is very hard to believe Brown's picture of a solid, loving female community in 1920, when she has a woman of that time call someone a flaming asshole. The seams show throughout.

These problems, jarring as they are, are still essentially cosmetic. The real weakness of the novel is in its Pollyannaish attitude towards the real problems of men and women. Having decided that men are O.K., Brown includes a few of them in her book; all except the evil Rifes (a family of villainous munitions manufacturers) are unbelievably sensitive and peaceable types. Whenever anything goes wrong, Cora, like Grandpa Walton, gives us a salt-of-the-earth piece of wisdom and puts everything to rights. The men don't betray the women. The women don't betray each other. If someone is crazy, he's harmless and cute and everyone is tolerant.

Brown spares us few television cliches. There is a boy becomes-a-man-amidst-the-stench-of-battle scene for each world war. The firemen's ball gets set on fire. The heroine dies jumping her horse, and other blase gems:

"Mother, Germany invaded Poland."

"Shut the screen door, honey, you'll let the flies in."

At the end the young writer buys the family farmhouse. Up on the roof of the barn she cries ecstatically, "Everything is possible. Pass the word."

IT WOULD be nice to see this world, in which women on lonely nights can find comfort with other women, in which deserted alcoholic wives simply open a speakeasy, in which lesbians can live together openly and peacefully in a small town, in which the good woman kills the villain and the police don't bother to investigate, in which lesbians and straight women, rich women and poor women live together without suspicion. It's not that all this isn't possible. But Rita Mae Brown never allows any of these conflicts to get out of hand. It's so much like those Lassie episodes we adored when we were kids, in which some heart-wrenching and highly unlikely disaster seemed ready to swallow everyone and was resolved in half an hour. Friendships are not ruined; no real psychic damage is caused. It's not that we lust after emotional violence or tragedy--it's just that the true potential of the current sexual struggle lies in revealing the dark side of our relationships and of our natures. There is nothing to gain by pretending that they don't exist, and authors who write T.V.-style escape stories that lull us into thinking everything's really O.K. are not fulfilling any useful role in a society as complex and strange as this one.